Mood changes associated with the menstrual cycle are examined in a collaborative study with investigators at Montefiore Hospital and Medical Center. The project seeks to determine the relationships between specific subtypes of premenstrual changes and the biological variables, the occurrence of affective or other mental disorders in the subjects or their families, and the degree of similarity between types of premenstrual change in subjects and their female first-degree relatives. Based on evaluations of Premenstrual Assessment Forms and interviews, four categories of subjects are selected for the biological studies. These include women who exhibit a depressive syndrome with atypical depressive features, agitated/anxious depressive features, only physical premenstrual changes, or no significant physical, behavioral, or mood changes. Biological variables of major focus include met-enkephalin, beta-endorphin, phenylethylamine, and monoamine oxidase in relation to each other and to sex steroids, gonadal and pituitary hormones, and changes in activity, sleep, and clinical states.